Conventionally, a roller hemming device is widely known that is configured to perform a hemming process, by use of a roller, with respect to a work such as a door subassembly of a car (for example, see Patent Literature 1).
The roller hemming device as mentioned above has a lower die on which the work is placed, and a processing device for hemming the work placed on the lower die by use of the roller.
When the roller hemming device performs the hemming process with respect to various works, the processing device can be widely used regardless of a type (shape, size and the like) of the work, whereas the lower die must be changed depending on a type of the work.
Therefore, the roller hemming device requires a space in which a plurality of lower dies depending on types of works are placed, which causes au increase in size of the roller hemming device.